The resurrection of Spock was perfect as filmed. The Genesis effect restored the body, but Vulcan religion restored his Katra. Almost from the start of ST, Vulcans were presented as having abilities beyond that of humans--and restoration of the living spirit, or soul transference was not out of place as one of those abilities. It added a greater, interesting dimension to the culture, rather than being painted as all about being cold, clinical--without something greater in their lives and reason to be.